3D Printing Methods | Every Method You Should Know

3D printing is not a single process. It is a category of manufacturing processes that share one principle: the object is built by adding material, usually layer by layer, instead of cutting it away from a solid block. Beyond that principle they have little in common. They use different feedstock, different energy sources and different physics, and they produce parts with different strengths, tolerances, surface finishes and costs.

The classification used here is ISO/ASTM 52900, the terminology standard maintained by ISO and the ASTM F42 committee on additive manufacturing. It sorts processes by how each layer is formed and bonded to the one below it. That produces seven process families: material extrusion, vat photopolymerisation, powder bed fusion, material jetting, binder jetting, sheet lamination and directed energy deposition. Wohlers Associates and the Additive Manufacturing Research Group at Loughborough University publish the same seven. One commercial process, cold spray, fits none of them and is covered at the end.

Within those seven families there are about thirty distinct commercial methods. This post covers all of them in family order. Each entry gives the mechanism, what the method is used for, and its main limitations. Manufacturers coin new trade names constantly for processes that already exist, so identifying the family a method belongs to is more useful than memorising the acronym.

Two notes on what follows. Of the thirty methods, only two can realistically be bought and run by an individual or a small business; that is set out in full further down. On the images: every method has a process diagram, because most of these machines are sealed and a diagram is the only way to show what happens inside. Where a freely licensed photograph of the real process exists it appears alongside. For roughly half of these methods no such photograph exists, because the machines are installed in a small number of industrial facilities and no usable picture has been released.

Material extrusion

Material is pushed through a moving nozzle and deposited onto the layer below, where it solidifies. This is the cheapest family to build a machine for and the only one that reached consumers at scale. It runs from desktop machines to gantries that print building walls.

Fused deposition modelling, FDM

Photo: An FDM nozzle laying down a layer at Makers Party, Bangalore (Subhashish Panigrahi, CC BY-SA 3.0)

Photo: An open-frame FDM machine with its filament spool and a tray of printed parts (Benoît Prieur, CC0)

A spool of thermoplastic filament is driven into a nozzle heated to between 190 and 260 degrees Celsius. The molten plastic is deposited along the path of each layer and fuses to the layer below as it cools. Fused deposition modelling is a Stratasys trademark; the open source term for the identical process is fused filament fabrication.

Used for: prototypes, jigs and fixtures, functional plastic parts and most consumer 3D printed products. It accounts for essentially every printer under a lakh.

Limitations: the bond between layers is weaker than the material within a layer, so parts fail preferentially along layer lines. Layer stepping is visible on curved surfaces. Material selection is covered in how to pick the best 3D printing filament and why PETG is the best material to 3D print.

Pellet extrusion, also called large format additive manufacturing

Photo: Oak Ridge National Laboratory's BAAM machine, pellet extrusion at furniture scale (Oak Ridge National Laboratory, CC BY 2.0)

Photo: The Shelby Cobra body printed on that machine (ENERGY.GOV, Public domain)

The same deposition principle at industrial scale. Raw thermoplastic pellets are fed into a hopper and melted by a rotating screw, which pumps them through a nozzle three to ten millimetres wide. The Cincinnati BAAM and comparable machines deposit tens of kilograms per hour. The car body in the second photograph was printed on the machine in the first.

Used for: boat hulls, vehicle body bucks, moulds, tooling and furniture. Pellets cost a fraction of filament per kilogram, which is what makes material cost viable at this scale.

Limitations: layer height is measured in millimetres, so surface finish is coarse and parts are almost always machined or sanded afterwards.

Bound metal deposition

Metal powder held in a wax and polymer binder is extruded as filament or rod on a machine mechanically similar to an FDM printer. The output is a green part with no structural strength. The binder is removed in a solvent or catalyst, then the part is sintered until the metal powder fuses. It shrinks by approximately 20 percent during sintering, which is compensated for in the model. Markforged sells this as ADAM and Desktop Metal as bound metal deposition.

Used for: low-volume metal parts, tooling and fixtures. It is the cheapest entry into metal printing because it requires no laser and no loose metal powder handling.

Limitations: the slowest and least dimensionally accurate metal process. The three-stage workflow adds days and a failed sinter loses the batch.

Concrete extrusion for construction

Photo: A concrete nozzle extruding a wall layer on site (Fizpaket, CC BY-SA 4.0)

Photo: A finished printed house in Wallenhausen, Germany (Looniverse, CC BY-SA 4.0)

A printable mortar is extruded through a nozzle of drainpipe diameter mounted on a gantry, crane or robot arm. Layers are 20 to 40 millimetres thick. Walls are printed hollow so reinforcement, services and insulation can be installed afterwards.

Used for: building walls. L&T Construction printed a post office in Bengaluru in 43 days, against roughly eight months by conventional construction. Tvasta, which originated at IIT Madras, has printed houses, an office at Garden Reach Shipbuilders in Kolkata and artificial reef modules in the Gulf of Mannar.

Limitations: printing replaces the wall-building stage only. Foundations, roofing, services and finishing remain conventional, so the time saving applies to one part of the schedule.

Bioprinting

Photo: An Organovo bioprinter, with two syringe heads instead of a hot end (National Center for Advancing Translational Sciences, Public domain)

The feedstock is a bio-ink: living cells suspended in a hydrogel. Syringe-driven heads deposit strands into a porous lattice rather than a solid mass, because cells inside a solid mass would not receive nutrients or oxygen. The hydrogel is crosslinked with light or a salt bath and the construct is transferred to an incubator. CELLINK is an established supplier.

Used for: research tissue models, drug testing and cosmetic testing substrates.

Limitations: printed tissue is limited in thickness and vascularisation. Printed organs for transplant are not a current capability.

Vat photopolymerisation

A tank of photosensitive liquid resin is cured selectively by light. The methods in this family differ only in how the light is delivered, and that variable determines resolution, speed and machine cost.

Stereolithography, SLA

Photo: A large stereolithography machine, orange panels blocking stray UV (Materialise NV, CC BY-SA 3.0)

Photo: A part off an SLA machine, with the smooth surface the process is bought for (Wizard191, CC BY-SA 3.0)

A single ultraviolet laser spot is steered by galvanometer-mounted mirrors, tracing the outline of each layer and then filling it. This is the oldest 3D printing process, patented in the 1980s and commercialised by 3D Systems. The orange panels on the machine in the photograph block stray ultraviolet light. Formlabs produces the common desktop machines.

Used for: master patterns, casting patterns, dental and medical models, and applications where surface finish and dimensional accuracy outweigh mechanical strength.

Limitations: a single point traces every layer, so print time scales with cured area and a full build plate takes far longer than one part. Cured photopolymer is brittle and degrades in sunlight.

Digital light processing, DLP

A digital projector using a chip of tilting micromirrors exposes an entire layer at once as a pixel image. The build plate is inverted above a tray with a transparent floor and the part is drawn upward out of the resin.

Used for: jewellery casting patterns, dental appliances and small batch production. Because the whole layer is exposed simultaneously, print time depends on part height only, not on the number of parts on the plate: forty rings take the same time as one.

Limitations: resolution is fixed by the projector's pixel count, so a larger build area gives coarser features. Parts are brittle, as with all photopolymer processes.

Masked stereolithography, MSLA

Photo: An Anycubic Photon Mono, a desktop MSLA machine, mid-print (UC Davis College of Engineering, CC BY 2.0)

The projector is replaced by a fixed ultraviolet LED array and an LCD panel that masks the light everywhere except the current layer outline. LCD panels are mass-produced commodities, which is why consumer resin printers are inexpensive. Elegoo, Anycubic and Phrozen all use this method.

Used for: miniatures, dental models, jewellery patterns and detailed display parts. Resolution is set by screen pixel pitch, approximately 17 microns on 8K panels, finer than any extrusion process achieves.

Limitations: the LCD panel is a consumable that degrades under continuous ultraviolet exposure. Resin requires gloves, ventilation and controlled disposal. Parts are brittle relative to printed thermoplastics.

Continuous liquid interface production, CLIP

Conventional bottom-up resin printers separate the part from the tray floor after every layer, which is slow and stresses fine features. Carbon removes that step using an oxygen-permeable window. Oxygen inhibits the curing reaction, so a thin layer of resin at the window stays permanently liquid, known as the dead zone. The part is drawn upward continuously rather than in discrete steps, then baked to trigger a second reaction that sets its final mechanical properties.

Used for: volume production parts, including athletic footwear midsoles, dental devices and automotive components.

Limitations: machines are leased rather than sold, and resins are proprietary to the platform.

Two-photon polymerisation

The resin cures only where two photons strike the same molecule simultaneously, a condition met only at the focal point of a tightly focused femtosecond laser and nowhere along the beam path. The focal point is steered within the volume of resin rather than across a surface.

Used for: microfluidic devices, micro-optics, medical microdevices and metamaterial lattices, with feature sizes below one micron.

Limitations: build volumes are measured in millimetres and machine cost is high. This is laboratory equipment rather than a production process.

Volumetric printing

A vial of resin rotates while a projector delivers a different calculated pattern at each angle. No single pattern cures anything; the object solidifies where the accumulated dose from all angles exceeds the curing threshold, forming all at once within the liquid. Computed axial lithography and xolography are the two current approaches.

Used for: research applications. Objects form in seconds to a minute, with no layers, no layer lines and no supports.

Limitations: resolution and part size are limited, and the process is only beginning to leave research.

Powder bed fusion

A thin layer of powder is spread across a bed and an energy source fuses it selectively. The bed lowers, another layer is spread, and the cycle repeats. The finished part sits buried in unfused powder that supported it throughout, which is why the polymer processes in this family need no support structures.

Selective laser sintering, SLS

The build chamber is held just below the melting point of the polymer powder, usually nylon, so the laser supplies only the final energy needed to sinter it. Machines come from EOS at the industrial end and Sinterit and Formlabs at benchtop scale.

Used for: functional end-use parts, drone and camera components, ducting and enclosures. Parts are close to isotropic, so there is no weak layer direction, and they can be nested in three dimensions to fill the build volume.

Limitations: surfaces are slightly porous and grainy, colour options are limited without dyeing, and only 50 to 70 percent of unused powder can be recycled into the next build.

Multi Jet Fusion, MJF

HP's process replaces the laser with inkjet heads and infrared lamps. A fusing agent is jetted where the layer must solidify and a detailing agent at the boundaries to limit heat spread and keep edges sharp. Infrared lamps then sweep the full bed, and only treated powder absorbs enough energy to fuse. HP publishes a direct comparison against SLS.

Used for: batch production of functional nylon parts. Because nothing is traced point by point, time per layer is largely independent of bed occupancy, and powder reuse rates exceed SLS.

Limitations: parts are grey to black rather than white, and the qualified material range is narrower than SLS.

Selective laser melting and direct metal laser sintering, SLM and DMLS

Photo: A Renishaw AM 400 laser melting system, sealed because the powder is a fire risk (Università di Pavia, CC BY 2.0)

Metal powder is fully melted, not sintered, by a fibre laser. The two names are vendor terminology for what the standards call laser powder bed fusion. The chamber is sealed and flooded with argon or nitrogen because heated metal powder in air is a fire and explosion risk, which is why the machine in the photograph is fully enclosed. Machines come from Nikon SLM Solutions, Colibrium Additive and EOS.

Used for: turbine components, fuel nozzles, orthopaedic implants, tooling with conformal cooling and rocket engines. This is the dominant process for high-value metal parts.

Limitations: unlike the polymer powder processes, this one requires supports, both to anchor the part against thermal distortion and to conduct heat from the melt pool. Parts are cut from the build plate and usually heat treated. Machine cost runs to crores.

Electron beam melting, EBM

An electron beam replaces the laser, which requires a vacuum because electrons scatter off air molecules. Beam power is higher than a laser, steering is by magnetic lenses with no moving mirrors, and the powder bed is preheated to several hundred degrees.

Used for: titanium orthopaedic implants and aerospace components. The preheat leaves parts with substantially lower residual stress than laser melting, which matters for crack-sensitive alloys.

Limitations: rougher surface finish, coarser powder, and part size capped by the vacuum chamber.

Selective heat sintering, SHS

A thermal print head, the same technology used in fax machines, passes over a bed of low-melting-point powder with individual heating elements switched on only over the part cross section.

Used for: it was developed as a low-cost office-scale powder bed process, and is listed here for completeness of the family.

Limitations: weak parts and almost no material choice. The process has largely disappeared commercially.

Material jetting

Inkjet heads deposit droplets of build material which are then solidified. This family gives the best surface finish and finest layer resolution of any 3D printing process, and the most fragile parts.

Photopolymer jetting, sold as PolyJet and MultiJet Printing

Photo: An Objet material jetting machine with the lid open, showing the jetting carriage (Zorro2212, CC BY-SA 3.0)

Hundreds of nozzles spray droplets of liquid photopolymer, and ultraviolet lamps on the same carriage cure each droplet as it lands. A gel-like secondary material is jetted simultaneously to support overhangs and is removed in water afterwards.

Used for: presentation models, anatomical and surgical models, and multi-material prototypes. Layer thickness reaches 14 microns, and because different resins can be jetted within one layer, a single part can combine full colour, transparent sections and both rigid and rubber-like regions.

Limitations: photopolymer parts are brittle and they yellow and weaken under ultraviolet exposure. Not a load-bearing process.

Drop on demand jetting

One nozzle deposits build material and a second deposits support material, each firing individual droplets only where required. A milling cutter planes every layer flat before the next is deposited, which is the source of the process's accuracy.

Used for: castable wax patterns for investment casting, principally in jewellery and dental laboratories. The pattern is printed, invested, burned out and replaced with metal.

Limitations: slow, and the patterns have no useful mechanical strength in themselves.

NanoParticle Jetting, NPJ

XJet jets a liquid suspension of metal or ceramic nanoparticles onto a heated build tray. The carrier liquid evaporates on contact, leaving solid particles, and the part is then sintered.

Used for: ceramic and metal parts with fine internal features. No loose powder is handled at any stage, which removes the principal safety requirement of metal printing, and support material dissolves in water, which allows internal channels in ceramic parts.

Limitations: a niche process with a small installed base and a limited qualified material set.

Binder jetting

Powder is spread in a bed as in powder bed fusion, but nothing is melted during printing. An inkjet head deposits liquid binder that bonds the powder at room temperature. With no heat applied, parts do not distort and need no supports. The output is a fragile green part that must be strengthened in a second stage.

Metal binder jetting

Photo: Binder printed onto a powder bed on an ExOne machine (Oak Ridge National Laboratory, CC BY 2.0)

Binder is printed onto metal powder and cured, then the green part is extracted from the bed and sintered, during which the binder burns off and the metal fuses. Shrinkage is approximately 20 percent and is compensated for in the model. Machines come from ExOne and Desktop Metal.

Used for: medium and high volume metal parts. The print head covers the full bed at inkjet speed regardless of part count, and there is no laser, no inert gas and no thermal distortion during printing, so machine and running costs sit far below laser powder bed fusion.

Limitations: the difficulty is in sintering. Parts distort as they shrink, achieved densities do not always match laser-melted parts, and green parts are fragile enough to break during handling.

Sand binder jetting

Binder is printed into a bed of foundry sand to produce a casting mould, including internal cores and channels that conventional pattern making cannot produce. Molten metal is then poured into the mould in the standard way. Voxeljet and ExOne supply the machines.

Used for: casting moulds and cores. This is the highest-volume industrial application of binder jetting by weight. It removes weeks of pattern making while leaving the casting process unchanged.

Limitations: it produces the mould, not the part, so it is only relevant where casting is already the production route.

Full colour binder jetting

Photo: Coloured binder on the powder bed of a full colour machine (Smokeonthewater, CC BY-SA 4.0)

The binder itself is coloured, applied from four heads mixing cyan, magenta, yellow and black as an office printer does. Every voxel can be a different colour, so a finished part carries full colour with no painting. The powder is typically gypsum or nylon.

Used for: figurines, architectural models, anatomical models and museum replicas.

Limitations: raw parts are chalky and brittle and must be sealed with cyanoacrylate or resin. No load-bearing applications.

Sheet lamination

Sheets of material are bonded to a stack and cut to the outline of each layer. It is the simplest principle in the field and the least used, because most of the material purchased becomes waste. It survives where its specific properties cannot be matched elsewhere.

Laminated object manufacturing, LOM

A continuous sheet of paper, polymer film or metal foil is fed across the build area, bonded down by a heated roller, and cut to the layer outline by a laser or blade. The cutter traces the outline only and dices the surrounding waste into squares for removal at the end.

Used for: large, dimensionally stable models where material cost matters. No resin and no powder is involved.

Limitations: every layer consumes a full sheet regardless of cross section, so waste is high, and removing diced waste from internal cavities is difficult or impossible.

Selective deposition lamination, SDL

Objects are built from standard A4 paper. Before each sheet is bonded, a colour inkjet head prints the layer's cross section onto it, so the edge of every sheet carries the correct colour. Adhesive is applied densely inside the part outline and sparsely outside it, so surrounding waste separates by hand.

Used for: full colour architectural and educational models. Finished parts are solid paper, recyclable and non-toxic.

Limitations: low strength, and the company that commercialised the process ceased trading, so machines and consumables are not readily available.

Ultrasonic additive manufacturing, UAM

A sonotrode vibrating at approximately 20 kHz is rolled over metal foil under pressure. The friction disperses surface oxides and the metals bond in the solid state, without melting. A CNC cutter trims each layer, so the process alternates between welding and machining. Fabrisonic supplies the machines.

Used for: components with embedded sensors, thermocouples or optical fibres, and parts combining dissimilar metals. With no melting, electronics can be sealed inside solid metal without thermal damage, which no other metal process permits.

Limitations: limited part geometry, and the alternating weld and machine cycle is slow.

Composite based additive manufacturing, CBAM

Impossible Objects prints a fluid onto a sheet of carbon or glass fibre in the shape of the layer, dusts the sheet with polymer powder that adheres only to the wet areas, then stacks and compresses the sheets under heat. Unbonded fibre is removed by blasting.

Used for: structural composite parts. Fibre runs continuously across each sheet, so strength is not restricted to the deposition direction as it is in extrusion-based composites. Parts compete with machined aluminium on strength to weight.

Limitations: limited geometric complexity compared with powder and resin processes, and a small supplier base.

Directed energy deposition

A focused energy source forms a melt pool and material is fed directly into it as the head moves. There is no powder bed and no fixed build envelope, so these processes can deposit material onto an existing component. That capability defines the family's applications.

Laser powder directed energy deposition

Photo: Laser cladding in practice: powder blown into the beam, melting onto the surface (Lucie Prokešová, CC BY-SA 4.0)

A nozzle on a robot arm or five-axis CNC head blows metal powder into a coaxial laser beam, melting it onto the surface below. It is sold as laser engineered net shaping, laser metal deposition and laser cladding; Optomec is a principal supplier.

Used for: repair and remanufacture above all. Worn turbine blade tips, damaged dies and scored shafts can have material rebuilt onto them and be machined back to specification, recovering components that would otherwise be scrapped.

Limitations: as-deposited surfaces are rough and machining afterwards is mandatory. Dimensional accuracy is well below powder bed fusion.

Wire arc additive manufacturing, WAAM

Photo: Wire arc deposition, with finished printed walls stacked at the left (Aleksandr Panfilov, CC BY 4.0)

A welding torch on a robot arm melts continuously fed metal wire with an electric arc, depositing beads several millimetres thick. Deposition rates reach kilograms per hour, the highest of any process not using an electron beam. Relativity Space built its launch vehicle programme around deposition at this scale.

Used for: large structural metal parts, ship propellers, pressure vessels and metres-long aerospace structures. Wire is cheaper than atomised powder and safer to store and handle, and the equipment is largely standard welding hardware.

Limitations: surface finish is very coarse and machining is always required. Heat input is high, so distortion and residual stress must be managed.

Electron beam additive manufacturing, EBAM

Photo: NASA's electron beam freeform fabrication, wire fed into a beam in vacuum (NASA, Public domain)

Wire is fed into an electron beam inside a vacuum chamber. Sciaky machines reach double-digit kilograms per hour, the highest metal deposition rate available.

Used for: large titanium and tantalum aerospace structures. The vacuum provides a very clean environment for reactive metals.

Limitations: part size is capped by the vacuum chamber and capital cost is high.

Cold spray, outside the seven families

Wohlers Associates records cold spray as the one commercial process that fits none of the seven categories. Compressed gas is heated and accelerated through a converging-diverging nozzle to supersonic velocity, carrying metal particles that strike the surface at 500 to 1000 metres per second. The particles bond by plastic deformation rather than melting: each flattens on impact and interlocks mechanically. Gas temperature stays several hundred degrees below the melting point of the metal. SPEE3D produces deployable systems.

Used for: rebuilding worn and corroded components, restoring dimensions and field repair. With no melt pool there is no oxidation, no heat-affected zone and no thermal distortion.

Limitations: geometric freedom is limited compared with true printing processes, and deposits are normally machined to final size.

Which methods you can actually buy in India

Photo: A desktop resin machine in a dental lab, one of the two families you can actually buy (Stutamad, CC BY-SA 4.0)

Of the thirty methods above, two can realistically be bought by an individual or a small business: material extrusion and masked stereolithography. Entry-level machines of both types sell in the tens of thousands of rupees through Indian resellers as of mid-2026. Every other method starts in lakhs, and most start in crores.

Cost is not the only barrier. Benchtop selective laser sintering requires powder handling and sieving equipment. Metal powder bed fusion requires inert gas supply, filtered extraction, a heat treatment furnace and a saw for plate removal. Binder jetting requires a sintering furnace. Directed energy deposition requires a robot cell. These are production facilities rather than appliances, and the machine is frequently the cheaper half of the installation. For the two families that can be bought outright, our breakdown of 3D printers ranked by quality and reliability covers the current options.

The third option is to use a method without owning it. If you have a model file and need the finished part, send us the file and we print it for you. You get the part without the machine, the calibration, the failed prints or the facility around it.

These methods in Indian industry

Photo: A rocket engine printed by laser powder bed fusion (Orbex, CC BY-SA 4.0)

AgniKul Cosmos, based at IIT Madras, produces complete rocket engines as single pieces of Inconel using laser powder bed fusion, with no welds, joints or fasteners. Its Agnilet engine was test fired at the Vikram Sarabhai Space Centre in 2022, and the company holds a US patent covering the design and manufacturing method.

ISRO, working with Wipro 3D, moved the PS4 engine that powers the fourth stage of the PSLV to laser powder bed fusion, consolidating the assembly into a single component and eliminating 19 weld joints. In construction, the L&T post office and the Tvasta buildings described earlier are complete and in use.

At the commercial end, material extrusion and masked stereolithography are what small studios across the country operate, including ours. The current state of that market is covered in the best 3D printing services in Mumbai.

How to select a method for a specific part

For any single part the decision usually resolves quickly:

• Low cost, fast, appearance not critical: material extrusion.
• Fine detail, sharp edges, smooth surface: masked stereolithography, or photopolymer jetting where budget allows.
• Functional plastic part with no weak direction: selective laser sintering or Multi Jet Fusion.
• Metal, small, geometrically complex: laser powder bed fusion.
• Metal, large, complexity not required: wire arc additive manufacturing or another directed energy deposition process.
• Repair or addition to an existing component: directed energy deposition, or cold spray where heat input must be avoided.
• Many identical parts, castable geometry: sand binder jetting for the mould, then conventional casting.
• Full colour direct from the machine: binder jetting or photopolymer jetting.

The first two lines cover the majority of real requirements. Most parts do not need a specialised process; they need a common one executed correctly.

Seven families, thirty methods

Seven process families, about thirty commercial methods, and one process outside the classification. They are grouped by how a layer is formed, not by material: metal appears in five of the seven families and plastic in five. Material extrusion and masked stereolithography are the only two that can be bought and run without a facility around them; everything else is an industrial installation or a service you buy parts from.

The practical consequence is that the phrase "3D printed" carries almost no information about a part on its own. The useful questions are which of these thirty methods produced it, and whether that method was the right choice for the requirement.

Image credits

The thirty process diagrams in this post are ours. The photographs are not, and are used under Creative Commons or public domain licences:

• An FDM nozzle laying down a layer at Makers Party, Bangalore - by Subhashish Panigrahi, via Wikimedia Commons, CC BY-SA 3.0
• An open-frame FDM machine with its filament spool and a tray of printed parts - by Benoît Prieur, via Wikimedia Commons, CC0
• Oak Ridge National Laboratory's BAAM machine, pellet extrusion at furniture scale - by Oak Ridge National Laboratory, via Wikimedia Commons, CC BY 2.0
• The Shelby Cobra body printed on that machine - by ENERGY.GOV, via Wikimedia Commons, Public domain
• A concrete nozzle extruding a wall layer on site - by Fizpaket, via Wikimedia Commons, CC BY-SA 4.0
• A finished printed house in Wallenhausen, Germany - by Looniverse, via Wikimedia Commons, CC BY-SA 4.0
• An Organovo bioprinter, with two syringe heads instead of a hot end - by National Center for Advancing Translational Sciences, via Wikimedia Commons, Public domain
• A large stereolithography machine, orange panels blocking stray UV - by Materialise NV, via Wikimedia Commons, CC BY-SA 3.0
• A part off an SLA machine, with the smooth surface the process is bought for - by Wizard191, via Wikimedia Commons, CC BY-SA 3.0
• An Anycubic Photon Mono, a desktop MSLA machine, mid-print - by UC Davis College of Engineering, via Wikimedia Commons, CC BY 2.0
• A Renishaw AM 400 laser melting system, sealed because the powder is a fire risk - by Università di Pavia, via Wikimedia Commons, CC BY 2.0
• An Objet material jetting machine with the lid open, showing the jetting carriage - by Zorro2212, via Wikimedia Commons, CC BY-SA 3.0
• Binder printed onto a powder bed on an ExOne machine - by Oak Ridge National Laboratory, via Wikimedia Commons, CC BY 2.0
• Coloured binder on the powder bed of a full colour machine - by Smokeonthewater, via Wikimedia Commons, CC BY-SA 4.0
• Laser cladding in practice: powder blown into the beam, melting onto the surface - by Lucie Prokešová, via Wikimedia Commons, CC BY-SA 4.0
• Wire arc deposition, with finished printed walls stacked at the left - by Aleksandr Panfilov, via Wikimedia Commons, CC BY 4.0
• NASA's electron beam freeform fabrication, wire fed into a beam in vacuum - by NASA, via Wikimedia Commons, Public domain
• A rocket engine printed by laser powder bed fusion - by Orbex, via Wikimedia Commons, CC BY-SA 4.0
• A desktop resin machine in a dental lab, one of the two families you can actually buy - by Stutamad, via Wikimedia Commons, CC BY-SA 4.0